India: Pest-Resistant Bt Brinjal Developed
News Oct 09, 2009
- M. L. Kapur, Sept. 21, 2009
The pest-resistant transgenic varieties of brinjal were developed under a centrally funded project spread over five years, using a process similar to the one used in the development of Bt cotton. Bt brinjal incorporates `Cry1Ac' gene, expressing insecticidal protein targeting the pest larvae.
Requesting anonymity, a senior team member associated with the project told `The Times of India' that when ingested by the larvae, the gene is activated in the insect's alkaline gut and binds to the gut wall, which later breaks down, allowing the Bt spores to invade the insect's body cavity, killing the larvae within a few days.
Fit For Human Consumption
He said an independent monitoring and evaluation committee has visited all the trial locations and submitted its report to the central department of bio-technology. A green signal for commercial release of the transgenic brinjal varieties is awaited. The Central Food Technology Research Institute (Mysore) has cleared it as "fit for human consumption".
An additional advantage of the transgenic varieties over the Bt hybrids is that once a farmer purchases the seeds of the varieties, he can re-use them for subsequent generations (in the case of hybrids, they need to purchase seeds every year). This reduces the dependence on seed supply chain, and in turn, reduces the seed input cost.
Bt Malapur local (S), Bt Manjari Gota, Bt Udupi Gulla, Bt Rabkavi local, Bt Kudachi local, Bt Go-112 and their non-Bt counterparts, along with Aruna as check, were evaluated in three locations at Kolhapur and Gadhinglaj in Maharashtra and at Kallolli Karnataka. Bt Go-112 and Bt Udupi Gulla, along with their non-Bt counterparts, were also evaluated at Brahmavar in coastal Karnataka.
All the Bt local varieties and their non-Bt counterparts were critically observed for levels of expression of Cry1Ac protein, pest infestation, occurrence of beneficial and non-target insects all through the trial period at regular intervals. Other agronomical observations were also recorded and economic benefits of the technology were calculated.
A clear advantage of the technology in terms of negligible shoot infestation and significantly reduced fruit infestation in all the Bt brinjal varieties compared to their non-Bt counterparts was observed. Pest infestation crossed the economic threshold levels in all non-Bt counterparts and the check.
Non-significant difference between the Bt and non-Bt counterparts for non-target insects and original respective traits of local varieties makes them preferred by the farmers. "The breeding scheme has ensured that the fruit and plant traits almost remained as in the original respective local varieties," the team member added.